I honestly have not had these issues with my Topsider. And I always pull out the Diesel oil from my engine and transmission cold in the off season. Again, it has really light duty use. I have changed the transmission and engine oils around 5x now. So give or take 10 oil pulls, I have not experienced any vacuum leak at the handle. I dont exert a huge amount of force on the pump when pumping as I am being careful inside the boat. I am sure there are other better units, but the price of the Topsider is what sold me.

I honestly have not had these issues with my Topsider. And I always pull out the Diesel oil from my engine and transmission cold in the off season. Again, it has really light duty use. I have changed the transmission and engine oils around 5x now. So give or take 10 oil pulls, I have not experienced any vacuum leak at the handle. I dont exert a huge amount of force on the pump when pumping as I am being careful inside the boat. I am sure there are other better units, but the price of the Topsider is what sold me.